This grant has facilitated the study of "Role of proteases in signal transductin and their disorders" during the last 3 years. The study was carried out under the following 4 categories.1. Gene expression and regulation of the proteasse and the related bioactive substances.2. Processing and transport of the precurcer proteins of the proteases and their inhibitors.3. Induction and modulstion of signals by proteases, and the interaction of protains by the aid of proteases.4. New functions of proteases1. Regulatory factors for gene exprssion of preproteachykinin, a precurcer protein of substance P and substance K.were found to be 43kD and attach to DNA thrugh ths lsucine zipper domsin of the molecules. With respect to calpains. in addition to the m- and mu-calpains. novel calpain genes were found to be expressed linited in skeletal and smooth muscles. The former calpain contained 94kD large subunit and the latter two types of large subunits ; type 1 which contains calmodulin domain and ty
… Morepe 2 without calmodulin domain.2. Proenzymes in the rat liver were fund to be Ca^<2+>-dependently activated in the tranagogi by the membrane-bound processingprotease. Progastrin secreted from the stomsch was also shown to be activated Ca^<2+>-dependently by the endopeptidase which recognizes dibasic amino acid sequence in the C-terminus of the molecule. Coagulation system of horseshoe crab was found to reside in the hemotocytes. Factor B, factor C, agglutinin and coagulation enzyme released from large granules and tackypressin from small granules were elucidated to form the cascade reaction system. Calpain, containing 94kD large subunit found in the nucleus was interpreted to be due to the transmembrane signal peptde in the large subunit.3. A satisfactory condition for the activation of calpain wes demonstrated to be the N-terminus cleavage of the large subunit, and ths subsequently released N-terminal peptides from the large and small subunits ware found to be chemotactic for neutrophils, monocytes and T and B lymphocytes The interaction of HIV and helper T lymphocyte was shown to be organized between the virus envglope glycoprotein pg120 and the T lymphocyte trptase and CD4 on the cell surtace.4. Multicatalytic high molecular weight proteass (proteasome) was shown to gain the special abllity to digest ubiquitinated protein through transformation of 20s complex to 28s in the presence of ATP.In the immunological event of antigen presentation by MHC class II, cathepsin B was sohwn to paly a crucial role in the prearation of the epitope peptides. Less